1. Technical Field
The present disclosure relates to surgical instruments and, more specifically, to surgical instruments including retractable and/or collapsible electrodes for treating, e.g., dissecting and/or coagulating, tissue.
2. Discussion of Related Art
The coagulation of bleeding blood vessels and tissue using electrically conductive suction tubes typically includes a combination of electrocautery and a suction device that is employed in surgery wherever excessive blood must be removed from the bleeding site in order to facilitate hemostasis of any bleeding vessels. More particularly, during certain surgical procedure, several layers of tissue must be penetrated to reach the operative field. When excising an organ, such as a gallbladder, the tissue surrounding the organ must often be penetrated and dissected before the organ can be removed. The tissues being dissected, however, often contain blood vessels, nerves, lymph vessels, and the like. The technique of blunt dissection is often used to prevent unnecessary damage caused by severing these vessels or nerves.
Blunt dissection, as opposed to sharp dissection, involves the use of a blunt surface to break through the tissue, thereby preventing the damage and bleeding caused by lasers and scalpels, the tools of sharp dissection. Hard surgical sponges, generally known as peanuts or Kittner sponges, or a surgeon's fingers are often used as blunt dissectors. A peanut is a tightly wound ball of absorbent material, such as gauze or other woven cotton, which is typically gripped with forceps and acts to abrade the tissue being dissected so that the dissection can be performed by either pulling on the tissue or by forcing the peanut through the tissue.
Laparoscopy, surgery performed through several small incisions or openings in the body rather than through a single large opening reduces the trauma and the risk of infection as compared to normal, open surgical procedures. The use of conventional blunt dissectors, such as the peanut, during laparoscopic procedures becomes difficult. For instance, peanuts, being secured only by forceps, can become loose in the body. Further, the view of the operative field often becomes obstructed by pieces of tissue, blood, and other bodily fluids produced during blunt dissection, necessitating the immediate need for both irrigation and aspiration of the operative field. Thus, the dissection must be stopped, the dissector must be removed, and an irrigator and/or aspirator must be inserted to remove the fluid and debris.
Electrosurgical suction coagulators which both coagulate and dissect tissue generally include a conductive suction tube having an insulating coating over all but a most distal portion of the tube so that the distal portion forms a generally annular ablating electrode. The distal end can be used as a blunt dissection device and/or a blunt coagulator. A suction source is attached to a proximal portion of the tube for evacuating excess fluid and debris from the surgical site through the distal end of the tube.